الفهرس 
Introduction and Aim Of WorkOnly 14 pages are availabe for public view
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Abstract
A kidney stone is a solid concretion or crystal aggregation formed in the kidneys from dietary minerals in the urine. Kidney stones typically leave the body by passage in the urine stream, and many stones are formed and passed without causing symptoms. If stones grow to sufficient size (usually at least 3 millimeters they can cause obstruction of the ureter. Ureteric obstruction causes post-renal azotemia and hydronephrosis.
The diagnosis of kidney stones is made on the basis of information obtained from the history, physical examination, urinalysis, and radiographic studies such as:
• X-RAY
• Ultrasound (U/S)
• Computerized Tomography (CT or CAT Scan)
• Intravenous Pyelogram (IVP)
• CT Urography:
When a stone causes no symptoms, watchful waiting is a valid option. For symptomatic stones, pain control is usually the first measure, using medications such as nonsteroidal anti-inflammatory drugs or opioids. Some stones can be shattered into smaller fragments using extracorporeal shock wave lithotripsy. Some cases require more invasive forms of surgery.
Extracorporeal shock wave lithotripsy (ESWL) is a non-invasive treatment of kidney stones using an acoustic pulse.
Extracorporeal shock wave lithotripsy (ESWL) is widely used in the treatment of symptomatic renal and ureteral stones but is not indicated for asymptomatic small stones. It is most effective for stones in the renal pelvis and upper ureter, and is less effective for larger stones (>1.5 cm), stones of harder composition (cysteine , calcium oxalate monohydrate), and stones in complex renal or ureteral locations (lower pole calyx or middle or lower ureter.
Although ESWL is highly effective, a number of urinary tract complications can occur such as:
■Incomplete stone fragmentation, (steinstress) which can lead to urinary tract obstruction.
■Renal parenchymal injury (subcapsular hematoma diagnosed by CT).
■A decline in glomerular filtration rate (over time).
■An elevation in blood pressure (caused by AV fistula) .
Aim of the work
The aim of this study is to build up a predictive model for prediction of success rate of ESWL and to define factors that have a significant impact on the stone free rate in patients with renal and ureteric stones.
Material and methods
We collected the data retrospectively and prospectively from three hundred and seventy patients with renal stones from Beni-Suef University Hospital Urology Department, ESWL device type Electrohydrolic.
We collected the data through the following:
• Full history taking (age, sex and family history).
• Thorough clinical examination.
• Radiological examination.
Results: Patients were grouped according to calculus attenuation value as groups 1(less than500), 2(500 to 1000) and 3 greater than 1000 HU. Of the 370 patients 321 (86.8%) underwent successful treatment. The rate of stone clearance was 100% (62 of 62 cases) in group1, 100% (226 of 226) in group 2 and 40.2% (33 of 82) in group 3. The success rate for calculi with an attenuation value of greater than 1000 HU was significantly lower than that for calculi with a value of less than 1000 HU (33 of 82 versus 288 of 288 cases, P-value =0.001 (Students t test).
Conclusion
In conclusion, our study proves that stone attenuation measured in HU is an important tool for stone treatment planning.
We also propose the expansion of inclusion criteria for ESWL candidates in cases of stones with an attenuation value of less than 500 HU with regards to stone size, patient age, renal function and coagulation profile.